DNN is not a black hat stuff -- it is simply "an open source web application framework ideal for creating, deploying and managing interactive web, intranet, and extranet sites securely."
http://www.dotnetnuke.com/In fact, I've seen some modules that allows for integration with Google products such as Google sitemap generator, even integration with Google Analytics
There will, however, be challenges when you will move to DNN -- from URL rewriting (I believe DNN supports search engine friendly URLs but not human friendly URLs), as well as dynamic URL configuration
There are a number of DNN-centric forums that you can check out as well as sites that offer DNN modules and skins